1. Field of the Invention
The invention pertains to casting a pipe seal in the wall of a concrete vessel for use in low pressure installations as for example, septic field distribution boxes and septic tanks. More specifically to an apparatus that mounts on a closure in one wall of the mold for molding a wall of the vessel and holds the seal between the walls of the wall mold.
2. Description of the Prior Art
U.S. Pat. No. 5,286,040 patented Feb. 15, 1994, by N. Gavin, describes designs for casting a pipe seal in the concrete wall of a septic tank. A hinged door on one wall of a concrete wall mold contains a closed cup shaped protrusion. A frustoconical plastic seal fits continuously over the closed bottom and frustoconical side wall of the cup and turns backward in a cylinder that extends from the larger diameter end of the frustoconical portion of the seal past the smaller end of the frustoconical portion of the seal.
When the door is closed, the cup positions the free end of the cylinder against the opposite wall of the concrete wall mold. When the concrete hardens, the door is opened, drawing the cup out of the concrete wall, leaving a conical opening in the concrete wall from the larger end of the cup leading to the open larger diameter end of the frustoconical seal.
The cylinder portion of the seal then lines the rest of the opening in the wall which is sealed by the frustoconical portion of the seal. Integrally molded portions of the seal comprising radially extending arms 31 ending in hollow cylindrical bosses that extend parallel to the axis of the seal (FIGS. 2-4) and annular radially extending flange 26 ending in axially extending rim 28 provide mounting points on the concrete wall and a cast-in anchor. U.S. Pat. No. 5,286,040, patented Feb. 15, 1994, is hereby incorporated by reference.
Additional designs for casting low pressure pipe seals in the concrete wall of a septic tank are described in U.S. Pat. No. 4,951,914, patented Aug. 28, 1990, by Meyers et at., 5,624,123, patented Apr. 29, 1997, by Meyers, and U.S. Pat. No. 5,941,535, patented Aug. 24, 1999, by Richard.
It is one object of the invention to mold a seal in a concrete wall of a vessel.
It is another object of the invention to mount the seal within a frustoconical frame designed for mounting on the door portion, or movable portion of one wall of a concrete wall mold.
In a mold for a concrete container for use in a low pressure septic system, a seal cast system includes: a first mold wall, a second mold wall spaced from the first mold wall for receiving liquid concrete between the first mold wall and the second mold wall for forming a concrete wall of the container,
a stiff tubular frame having a first end, a second end, and an axis through the first end and the second end, the first end of the frame attached sealingly to the first mold wall between the first mold wall and the second mold wall, the frame extending axially toward the second mold wall,
a one piece molded flexible tubular seal comprising a first end in the tubular frame, the seal extending axially from a second end of the tubular frame toward the second mold wall, a second, open end of the flexible seal sealingly contacting the second mold wall,
the second end of the tubular frame extending toward the second wall into an annular recess on the seal formed by a portion of the seal folding back from the second end of the seal toward the first end of the seal, to the bottom of the recess, and
radially extending means, molded on the seal, for anchoring the seal in the concrete wall when the concrete wall is formed by the first and second mold walls. Preferably the second end of the frame is smaller than the first end of the frame, and the second end of the tubular seal is larger than the first end of the tubular seal.
A plurality of fasteners extending through said first mold wall into said frame are spaced radially from the axis.
The first end of the tubular seal is closed, and the seal includes an annular notch in the seal around the axis adjacent to the first end of said tubular seal for removing the closed end of the seal.